As some of you might know, I recently purchase a 1964 Sears Suburban 725. The engine is a B&S 19D (7.25HP). I am learning as I go. Last night I took the wire off the plug and pull started it using a rope.....no spark. Tried it a couple of times with no visible arc. I even held the end of the wire to see if I could feel anything. Nope

The nice folks over at B&S emailed a copy of the parts manual for the tractor. It appears that the engine has a magneto flywheel and armature. I believe I understand how this works. I need help trouble shooting. Tonight I am going to look for loose wires. What else could it be?

nice machine tho you got pics of it? if its not that id check the carb or drain old gas if there is any carb might just need a good cleaning its a pain testing for spark on a pull start I ushally have a buddy help me one pulls while the other one checks just easyer there is also spark plug testers you can get and they are ushally good I gotta thank my grandpa I still have his tools from the good old days haha.

dump some gas down her and see what she does she should burp or fart atleast.

I took the wire off the plug and layed it next to the exhaust to see if I could see a spark/arc. None. Someone here at work suggested that I take off the cover and see if the mangets are rusting. If so clean them up and then see what happens. I also read online to disconnect the stop wire and see if that helps. I am dying to here this things run.

hmmm sounds like a points or condenser or even both bad in this machine

Does it have them? I don't that I see that in the parts diagrams. Only the "flywheel magneto" and the "amature assembly". I was assuming that the magnets on the flywheel pass by the armature (coil) and create and electrical current that travels straight to the spark plug. Does this sound right????

Electronic coils did not come out till 1981. Look under flywheel for pts and cond., replace them both. If after you have replaced pts/cond,and you still don't have spark, then replace coil. After looking at pictures,does this mower have a coil like a car and on the outside of engine?

Got a chance to work on the 725 last night. I got the starter pully off using a gear puller. This gave me a chance to get a good look at the magneto and the armature. In the pictures below, I took a brass wire wheel to the magnets to clean them up. They had a layer of rust over them. Next I need to remove the armature and clean that up.

You all were right. I found the breaker point. I also attached a picture of that. When I removed the cover (sealed), I found that the parts contained within looked like new. I guess that cover has been doing its job. I guess I should also clean the point and check the gap.

When I spun the flywheel, I could see the breaker plunger back up (making the breaker make contact) right after of the compression stroke.

At the very least, I would clean up the points and check the gap.(if they don't look too bad) And, I would replace the condenser. Then put the flywheel on, with the nut just finger tight or a little more, and then check for spark again.

The best thing to do is first get a good points file... Sometimes you need to clean the point 5-6 time before they will spark again... Next I would get a drill socket adapter so you can put a socket in your drill... Put the socket on the big nut on the flywheel and take the spark plug out and lay it with the wire attached on the engine head... Use the drill to spin the engine over and make sure it's turning the right way... Now you can watch for spark and play with the points... Anytime you park a tractor engine with points for a long time you will need to clean them to get it running again...

Register Now

In order to be able to post messages on the MyTractorForum.com - The Friendliest Tractor Forum and Best Place for Tractor Information forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:

Password

Please enter a password for your user account. Note that passwords are case-sensitive.

Password:

Confirm Password:

Email Address

Please enter a valid email address for yourself.

Email Address:

OR

Log-in

User Name

Password

Remember Me?

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.